Free
You inhale about 25,000 times a day.
You swallow dozens of times during a single meal. Your heart beats between 60 and 100 times a minute, when you are at rest. Suppose you had to consciously tell each and every muscle how and when to contract and relax. You wouldn’t have much time to do anything else! Luckily, you don’t have to, thanks to involuntary muscles. These muscles are beyond your control. They do their work while you live your life.
There are two types of involuntary muscles: smooth muscles and cardiac muscles.
